Apparatus and method for beam failure recovery in wireless communication system

ABSTRACT

The disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-Generation (4G) communication system, such as long term evolution (LTE). A method for operating a terminal in wireless communication system is provided. The method includes receiving, from a base station, system information including at least one parameter associated a paging operation, and monitoring a paging occasion (PO) that is determined based on the at least one parameter, during a discontinuous reception (DRX) operation.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. §119(a) of a Korean patent application number 10-2018-0039850, filed onApr. 5, 2018, in the Korean Intellectual Property Office, the disclosureof which is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates generally to a wireless communication system.More particularly, the disclosure relates to an apparatus and a methodfor beam failure recovery (BFR) in the wireless communication system.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of 4th generation (4G) communication systems, efforts havebeen made to develop an improved 5th generation (5G) or pre-5Gcommunication system. Therefore, the 5G or pre-5G communication systemis also called a ‘beyond 4G network’ or a ‘post long term evolution(LTE) System’.

The 5G communication system is considered to be implemented in higherfrequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higherdata rates. To decrease propagation loss of the radio waves and increasethe transmission distance, the beamforming, massive multiple-inputmultiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are discussed in5G communication systems.

In addition, in 5G communication systems, development for system networkimprovement is under way based on advanced small cells, cloud radioaccess networks (RANs), ultra-dense networks, device-to-device (D2D)communication, wireless backhaul, moving network, cooperativecommunication, coordinated multi-points (CoMP), reception-endinterference cancellation and the like.

In the 5G system, hybrid frequency shift keying (FSK) and quadratureamplitude modulation (FQAM) and sliding window superposition coding(SWSC) as an advanced coding modulation (ACM), and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse codemultiple access (SCMA) as an advanced access technology have beendeveloped.

The 5G system needs to utilize an adequate beam for effectivebeamforming. For doing so, various methods for selecting, tracking, ormaintaining an optimal beam are under discussion.

The above information is presented as background information only toassist with an understanding of the disclosure. No determination hasbeen made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the disclosure.

SUMMARY

Aspects of the disclosure are to address at least the above-mentionedproblems and/or disadvantages and to provide at least the advantagesdescribed below. Accordingly, an aspect of the disclosure is to providean apparatus and a method for effectively performing beam failurerecovery (BFR) in a wireless communication system.

Another aspect of the disclosure is to provide an apparatus and a methodfor effectively monitoring paging in a wireless communication system.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an embodiment of the disclosure, a method for BFR in awireless communication system is provided. The method includestransmitting a preamble signal for random access (RA), receiving a firstmessage including a RA response (RAR) corresponding to the preamblesignal, and transmitting a second signal corresponding to the firstmessage, wherein the second message may include at least one of acell-radio network temporary identifier (ID) (C-RNTI) media accesscontrol (MAC) control element (CE) or a BFR MAC CE.

According to an embodiment of the disclosure, a method for operating aterminal in wireless communication system is provided. The methodincludes receiving, from a base station, system information including atleast one parameter associated a paging operation, and monitoring apaging occasion (PO) that is determined based on the at least oneparameter, during a discontinuous reception (DRX) operation. Herein, thePO includes at least one physical downlink control channel (PDCCH)monitoring occasion, and the at least one PDCCH monitoring occasioncorresponds to at least one synchronization signal block (SSB)transmitted from the base station.

According to an embodiment of the disclosure, a method for operating abase station in wireless communication system is provided. The methodincludes transmitting, to a terminal, system information including atleast one parameter associated a paging operation, and transmitting, tothe terminal, a paging message in a PO that is determined based on theat least one parameter, during a DRX operation of the terminal. Herein,the PO includes at least one PDCCH monitoring occasion, and wherein theat least one PDCCH monitoring occasion corresponds to at least one SSBtransmitted from the base station.

According to an embodiment of the disclosure, a method for operating aterminal in wireless communication system is provided. The methodincludes receiving, from a base station, system information includingfirst configuration information associated with a request of systeminformation messages that are provided on demand, and transmitting, tothe base station, a signal for requesting at least one of the systeminformation messages based on the first configuration information.Herein, if the first configuration information includes oneconfiguration entry, the one configuration entry is used to request allof the system information messages.

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates a wireless communication system according to anembodiment of the disclosure;

FIG. 2 illustrates a configuration of a base station in a wirelesscommunication system according to an embodiment of the disclosure;

FIG. 3 illustrates a configuration of a terminal in a wirelesscommunication system according to an embodiment of the disclosure;

FIG. 4A illustrates a configuration of a communication unit in awireless communication system according to an embodiment of thedisclosure;

FIG. 4B illustrates a configuration of a communication unit in awireless communication system according to an embodiment of thedisclosure;

FIG. 4C illustrates a configuration of a communication unit in awireless communication system according to an embodiment of thedisclosure;

FIG. 5 illustrates a flowchart of a terminal for performing a randomaccess (RA) procedure in a wireless communication system according to anembodiment of the disclosure;

FIG. 6 illustrates a Msg3 structure in a wireless communication systemaccording to an embodiment of the disclosure;

FIG. 7 illustrates a flowchart of a terminal for generating a mediaaccess control (MAC) control element (CE) in a wireless communicationsystem according to an embodiment of the disclosure;

FIG. 8 illustrates a flowchart of a terminal for performing a RAprocedure in a wireless communication system according to an embodimentof the disclosure;

FIG. 9 illustrates a beam failure recovery (BFR) MAC-CE structureincluded in a Msg3 in a wireless communication system according to anembodiment of the disclosure;

FIG. 10 illustrates a cell-radio network temporary identifier (ID)(C-RNTI) MAC-CE structure included in a Msg3 in a wireless communicationsystem according to an embodiment of the disclosure;

FIG. 11 illustrates a flowchart of a terminal for generating a MAC CE ina wireless communication system according to an embodiment of thedisclosure;

FIG. 12 illustrates a flowchart of a terminal for performing a RAprocedure in a wireless communication system according to an embodimentof the disclosure;

FIG. 13 illustrates a BFR MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure;

FIG. 14 illustrates an RNTI MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure;

FIG. 15 illustrates a flowchart of a terminal for generating a MAC CE ina wireless communication system according to an embodiment of thedisclosure;

FIG. 16 illustrates a flowchart of a terminal for performing a RAprocedure in a wireless communication system according to an embodimentof the disclosure;

FIG. 17 illustrates a type1 BFR MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure;

FIG. 18 illustrates a type2 BFR MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure;

FIG. 19 illustrates a C-RNTI MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure;

FIG. 20 illustrates a flowchart of a terminal for generating a MAC CE ina wireless communication system according to an embodiment of thedisclosure;

FIG. 21 illustrates a configuration of a physical downlink controlchannel (PDCCH) monitoring occasion in a wireless communication systemaccording to an embodiment of the disclosure;

FIG. 22 illustrates a paging occasion (PO) monitored by a terminal in awireless communication system according to an embodiment of thedisclosure;

FIG. 23 illustrates a configuration of a PDCCH monitoring occasion in awireless communication system according to an embodiment of thedisclosure; and

FIG. 24 illustrates a PO monitored by a terminal in a wirelesscommunication system according to an embodiment of the disclosure.

Throughout the drawings, like reference numerals will be understood torefer to like parts, components and structures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thedisclosure. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of thedisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of thedisclosure is provided for illustration purpose only and not for thepurpose of limiting the disclosure as defined by the appended claims andtheir equivalents.

It is to be understood that the singular form “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

In embodiments of the disclosure to be described below, a hardwareapproach will be described as an example. However, since the embodimentsof the disclosure include a technology using both hardware and software,the embodiments of the disclosure do not exclude a software-basedapproach.

Embodiments of the disclosure provide an apparatus and a method forperforming beam failure recovery (BFR) in a wireless communicationsystem. More specifically, the disclosure provides a technique forproviding uplink information and prioritizing a logical channel for theBFR in the wireless communication system.

Terms indicating signals, terms indicating messages, terms indicatingchannels, terms indicating control information, terms indicating networkentities, and terms indicating components of a device, which are used inthe following descriptions, are for the sake of explanations.Accordingly, the disclosure is not limited to the terms to be described,and may use other terms having technically identical meaning.

The disclosure provides embodiments using terms used in somecommunication standards (e.g., 3rd Generation Partnership Project(3GPP)) by way of example. Embodiments of the disclosure may be easilyused in other communication systems.

FIG. 1 illustrates a wireless communication system according to anembodiment of the disclosure.

Referring to FIG. 1, a base station 110, a terminal 120, and a terminal130, as some of nodes which use a radio channel in the wirelesscommunication system. While FIG. 1 depicts the single base station, thesame or similar base station to the base station 110 may be furtherincluded.

The base station 110 is a network infrastructure which provides radioaccess to the terminals 120 and 130. The base station 110 has coveragedefined as a geographical area, based on a signal transmission distance.The base station 110 may be referred to as an access point (AP), anenodeb (eNB), a 5th generation node (5G node), a 5G nodeb (gNodeB, gNB),a wireless point, a transmission/reception point (TRP), or other termhaving a technically equivalent meaning.

The terminal 120 and the terminal 130 each are a device used by a user,and communicate with the base station 110 over a radio channel. In somecases, at least one of the terminal 120 and the terminal 130 may operatewithout user's involvement. For example, at least one of the terminal120 and the terminal 130 performs machine type communication (MTC) andmay not be carried by the user. The terminal 120 and the terminal 130each may be referred to as a user equipment (UE), a mobile station, asubscriber station, a remote terminal, a wireless terminal, a userdevice, or other term having a technically equivalent meaning.

The base station 110, the terminal 120, and the terminal 130 maytransmit and receive radio signals in a millimeter wave (mmWave) band(e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz). To improve channel gain, thebase station 110, the terminal 120, and the terminal 130 may conductbeamforming. Herein, the beamforming may include transmit beamformingand receive beamforming. For example, the base station 110, the terminal120, and the terminal 130 may apply directivity to a transmit signal ora receive signal. For doing so, the base station 110 and the terminals120 and 130 may select serving beams 112, 113, 121, and 131 through beamsearch or beam management. After the serving beams 112, 113, 121, and131 are selected, communications may be performed using resources whichare quasi co-located (QCL) with resources which carry the serving beams112, 113, 121, and 131.

If large-scale properties of a channel which carries a symbol on a firstantenna port may be inferred from a channel which carries a symbol on asecond antenna port, the first antenna port and the second antenna portmay be said to be QCL. For example, the large-scale properties mayinclude at least one of delay spread, Doppler spread, Doppler shift,average gain, average delay, and spatial receive parameter.

FIG. 2 illustrates a base station in a wireless communication systemaccording to an embodiment of the disclosure. FIG. 2 depicts aconfiguration of the base station 110. A term, such as ‘portion’ or‘˜er’ indicates a unit for processing at least one function oroperation, and may be implemented using hardware, software, or acombination of hardware and software.

Referring to FIG. 2, the base station includes a wireless communicationunit 210, a backhaul communication unit 220, a storage unit 230, and acontrol unit 240.

The wireless communication unit 210 may transmit and receive signalsover a radio channel. For example, the wireless communication unit 210performs a conversion function between a baseband signal and a bitstring according to a physical layer standard of the system. Forexample, in data transmission, the wireless communication unit 210generates complex symbols by encoding and modulating a transmit bitstring. In addition, in data reception, the wireless communication unit210 restores a receive bit string by demodulating and decoding abaseband signal.

The wireless communication unit 210 up-converts the baseband signal to aradio frequency (RF) band signal, transmits it via an antenna, anddown-converts an RF band signal received via an antenna to a basebandsignal. For doing so, the wireless communication unit 210 may include atransmit filter, a receive filter, an amplifier, a mixer, an oscillator,a digital to analog convertor (DAC), an analog to digital convertor(ADC), and the like. In addition, the wireless communication unit 210may include a plurality of transmit and receive paths. Further, thewireless communication unit 210 may include at least one antenna arrayincluding a plurality of antenna elements.

In view of hardware, the wireless communication unit 210 may include adigital unit and an analog unit, and the analog unit may include aplurality of sub-units according to an operating power and an operatingfrequency. The digital unit may include at least one processor (e.g., adigital signal processor (DSP)).

As such, the wireless communication unit 210 transmits and receives thesignals. Hence, whole or part of the wireless communication unit 210 maybe referred to as a transmitter, a receiver, or a transceiver. In thefollowing, the transmission and the reception over the radio channelembrace the above-stated processing of the wireless communication unit210.

The backhaul communication unit 220 provides an interface forcommunicating with other nodes in the network. For example, the backhaulcommunication unit 220 converts a bit sting transmitted from the basestation to another node, for example, to another access node, anotherbase station, an upper node, or a core network, to a physical signal,and converts a physical signal received from the other node to a bitstring.

The storage unit 230 stores a basic program for operating the basestation, an application program, and data, such as configurationinformation. The storage unit 230 may include a volatile memory, anon-volatile memory, or a combination of a volatile memory and anon-volatile memory. The storage unit 230 provides the stored data inresponse to a request of the control unit 240.

The control unit 240 controls general operations of the base station.For example, the control unit 240 transmits and receives signals throughthe wireless communication unit 210 or the backhaul communication unit220. In addition, the control unit 240 records and reads data in andfrom the storage unit 230. The control unit 240 may execute functions ofa protocol stack requested by a communication standard. According toother embodiment of the disclosure, the protocol stack may be includedin the wireless communication unit 210. For doing so, the control unit240 may include at least one processor. According to various embodimentsof the disclosure, the control unit 240 may control the base station tocarry out operations to be explained according to various embodiments.

FIG. 3 illustrates a configuration of a terminal in a wirelesscommunication system according to an embodiment of the disclosure. FIG.3 depicts a configuration of the terminal 120. A term, such as ‘portion’or ‘˜er’ indicates a unit for processing at least one function oroperation, and may be implemented using hardware, software, or acombination of hardware and software.

Referring to FIG. 3, the terminal includes a communication unit 310, astorage unit 320, and a control unit 330.

The communication unit 310 may transmit and receive signals over a radiochannel. For example, the communication unit 310 performs a conversionfunction between a baseband signal and a bit string according to aphysical layer standard of the system. For example, in datatransmission, the communication unit 310 generates complex symbols byencoding and modulating a transmit bit string. Moreover, in datareception, the communication unit 310 restores a receive bit string bydemodulating and decoding a baseband signal. In addition, thecommunication unit 310 up-converts the baseband signal to an RF bandsignal, transmits it via an antenna, and down-converts an RF band signalreceived via the antenna to a baseband signal. For example, thecommunication unit 310 may include a transmit filter, a receive filter,an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

Furthermore, the communication unit 310 may include a plurality oftransmit and receive paths. Further, the communication unit 310 mayinclude at least one antenna array including a plurality of antennaelements. In view of the hardware, the communication unit 310 mayinclude a digital circuit and an analog circuit (e.g., an RF integratedcircuit (RFIC)). Herein, the digital circuit and the analog circuit maybe implemented as a single package. In addition, the communication unit310 may include a plurality of RF chains. Further, the communicationunit 310 may perform the beamforming.

As such, the communication unit 310 transmits and receives the signals.Hence, whole or part of the communication unit 310 may be referred to asa transmitter, a receiver, or a transceiver. Hereafter, the transmissionand the reception over the radio channel embrace the above-statedprocessing of the communication unit 310.

The storage unit 320 stores a basic program for operating the terminal,an application program, and data, such as configuration information. Thestorage unit 320 may include a volatile memory, a non-volatile memory,or a combination of a volatile memory and a non-volatile memory. Thestorage unit 320 provides the stored data according to a request of thecontrol unit 330.

The control unit 330 controls general operations of the terminal. Forexample, the control unit 330 transmits and receives signals through thecommunication unit 310. In addition, control unit 330 records and readsdata in and from the storage unit 320. The control unit 330 may executefunctions of a protocol stack required by a communication standard. Fordoing so, the control unit 330 may include at least one processor ormicroprocessor, or may be part of a processor. Part of the communicationunit 310 and the control unit 330 may be referred to as a communicationprocessor (CP). According to various embodiments of the disclosure, thecontrol unit 330 may control the terminal to carry out operations, to beexplained, according to various embodiments.

FIGS. 4A to 4C illustrate a configuration of a communication unit in awireless communication system according to various embodiments of thedisclosure. FIGS. 4A, 4B, and 4C depict a detailed configuration of thewireless communication unit 210 of FIG. 2A or the communication unit 310of FIG. 3. More specifically, FIGS. 4A, 4B, and 4C depict components forperforming the beamforming, as part of the wireless communication unit210 of FIG. 2A or the communication unit 310 of FIG. 3.

Referring to FIG. 4A, the wireless communication unit 210 or thecommunication unit 310 includes an encoder and modulator 402, a digitalbeamformer 404, a plurality of transmit paths 406-1 through 406-N, andan analog beamformer 408.

The encoder and modulator 402 performs channel encoding. For the channelencoding, at least one of low density parity check (LDPC) code,convolution code, and polar code may be used. The encoder and modulator402 generates modulation symbols through constellation mapping.

The digital beamformer 404 beamforms a digital signal (e.g., themodulation symbols). For doing so, the digital beamformer 404 multipliesthe modulation symbols by beamforming weights. Herein, the beamformingweights are used to change an amplitude and a phase of the signal, andmay be referred to as a precoding matrix or a precoder. The digitalbeamformer 404 outputs the digital-beamformed modulation symbols to thetransmit paths 406-1 through 406-N. In doing so, according to massivemultiple-input multiple-output (MIMO) transmission, the modulationsymbols may be multiplexed or the same modulation symbols may be fed tothe transmit paths 406-1 through 406-N.

The transmit paths 406-1 through 406-N convert the digital-beamformeddigital signals to analog signals. For doing, the transmit paths 406-1through 406-N each may include an inverse fast fourier transform (IFFT)operator, a cyclic prefix (CP) adder, a DAC, and an up-converter. The CPadder is used for orthogonal frequency division multiplexing (OFDM), andmay be excluded if another physical layer scheme (e.g., filter bankmulti-carrier (FBMC)) is applied. For example, the transmit paths 406-1through 406-N provide an independent signal process for a plurality ofstreams generated through the digital beamforming. Notably, depending onthe implementation, some of the components of the transmit paths 406-1through 406-N may be used in common.

The analog beamformer 408 beamforms the analog signals. For doing so,the digital beamformer 404 multiplies the analog signals by thebeamforming weights. Herein, the beamforming weights are used to changethe amplitude and the phase of the signal. More specifically, the analogbeamformer 408 may be configured as shown in FIG. 4B or FIG. 4C,according to a connection structure between the transmit paths 406-1through 406-N and the antennas.

Referring to FIG. 4B, signals inputted to the analog beamformer 408 areconverted in phase/amplitude, amplified, and then transmitted via theantennas. In doing so, signals of each path are transmitted viadifferent antenna sets, that is, antenna arrays. Signals inputted in afirst path are converted by phase/amplitude converters 412-1-1 through412-1-M to signal strings having different or the same phase/amplitude,amplified by amplifiers 414-1-1 through 414-1-M, and then transmittedvia the antennas. In addition, signals inputted in a first path areconverted by phase/amplitude converters 412-N−1 through 412-N-M tosignal strings having different or the same phase/amplitude, amplifiedby amplifiers 414-N−1 through 414-N-M, and then transmitted via theantennas.

Referring to FIG. 4C, signals inputted to the analog beamformer 408 areconverted in phase/amplitude, amplified, and then transmitted viaantennas. In doing so, signals of each path are transmitted via the sameantenna set, that is, the same antenna array. Signals inputted in thefirst path are converted by the phase/magnitude converters 412-1-1through 412-1-M to signal strings having different or the samephase/amplitude, and amplified by the amplifiers 414-1-1 through414-1-M. Next, to transmit via a single antenna array, the amplifiedsignals are summed by adders 416-1-1 through 416-1-M based on theantenna element and then transmitted via the antennas.

The independent antenna array is used per transmit path in FIG. 4B, andthe transmit paths share the single antenna array in FIG. 4C. However,according to another embodiment of the disclosure, some transmit pathsmay use the independent antenna array, and the rest transmit paths mayshare one antenna array. Further, according to yet another embodiment ofthe disclosure, by applying a switchable structure between the transmitpaths and the antenna arrays, a structure which adaptively changesaccording to a situation may be used.

With advent of smart phones, use of a wireless communication network anda portable electronic device by the user is exponentially growing, and,to accomplish a higher data rate, a 5G communication system considersimplementation at a super-high frequency (mmWave) band (e.g., a 60 GHzband). In order to obviate a path loss and to increase a deliverydistance of propagation at the super-high frequency band, beamforming,MIMO, full dimensional MIMO (FD-MIMO), array antenna, analogbeam-forming, and large scale antenna techniques are discussed in the 5Gcommunication system.

Additionally, for an improvement in network of the system, the 5Gcommunication system develops techniques, such as evolved small cell,advanced small cell, cloud radio access network (cloud RAN), ultra-densenetwork, device to device (D2D) communication, wireless backhaul, movingnetwork, cooperative communication, coordinated multi-points (COMP), andinterference cancellation.

Besides, the 5G communication system is working on hybrid frequencyshift keying (FSK) and quadrature amplitude modulation (QAM) modulation(FQAM) and sliding window superposition coding (SWSC) as advanced codingmodulation (ACM), filter bank multi carrier (FBMC), non-orthogonalmultiple access (NOMA), and sparse code multiple access (SCMA) as anadvanced access technology.

Now, operations for improving terminal's performance are explainedaccording to various embodiments of the disclosure, if beam performancedegrades while a terminal and a base station transmit and receiveinformation using multiple beams. Such beam performance degradation maybe referred to as beam failure, and a process for recovering it may bereferred to as BFR.

A radio resource control (RRC) connected terminal may perform wirelesscommunication with the base station using one or more serving beams.Such a serving beam may be measured/observed and reported in associationwith channel state information (CSI)-reference signal (RS) orsynchronization signal (SS) block (SSB).

If the CSI-RS based serving beam is used, the network may configure oneor more (mapped to different beams) unique preambles and/or one or morecontention free random access (RA) resources to the terminal for thesake of the serving BFR, and conduct signal transmission. Herein, suchconfiguration information may be transmitted in a specific informationelement, for example, BFR config in a downlink RRC/media access control(MAC)/physical (PHY) signal provided from a specific network to theterminal. In doing so, the contention free RA resource may have beamassociation which is received at the base station using the same beamdirection as the configured unique CSI-RS.

If the SSB based serving beam is used, the network may set one or more(mapped to different beams) unique preambles and/or one or morecontention free RA resources to the terminal for the sake of the servingBFR, and conduct signal transmission. Herein, such configurationinformation may be transmitted in a specific information element, forexample, in BFR Config in a downlink RRC/MAC/PHY signal provided from aspecific network to the terminal. In doing so, each contention free RAresource may have the beam association which is received at the basestation using the same beam direction as the configured unique SSB.

If a measured channel quality of any CSI-SS or SSB beams associated withthe configured contention free RA resource does not exceed a specificthreshold BFCandidateBeamThreshold which is preset by the network, theterminal may perform existing contention based RA using the contentionbased RA resource. If the measured channel quality of any CSI-SS or SSBbeams associated with the configured contention free RA resource exceedsthe specific threshold BFandidateBeamThreshold which is preset by thenetwork, the terminal may perform the contention free RA by selectingresources as follows.

The terminal may conduct the contention free RA by selecting resourceswhich may use beams of the best channel quality.

The terminal may conduct the contention free RA for K-ary resources byselecting the K-ary resources in order having the beam of the bestchannel quality. At this time, K may be a value included in a downlinksignal (RRC/MAC/PHY) which is configured and provided by the network

It is noted that the resources for the contention based RA and specificbeams (e.g., SSBs) associated therewith may be different from theresources for the contention free RA and specific beams (e.g., CS-RSs)associated therewith. In this case, the terminal needs to measure onlybeams associated to the contention based RA resources and determineresources for transmitting the preamble for the contention based RA.

As a result, if not using the contention free RA for the BFR (e.g., ifthe measured beam quality falls below the threshold or the resource isnot allocated), the terminal may not provide the network with properbeam information (CSI-RS identifier (ID) and the measurement value) dueto the different beam association although the contention based RA isused. Notably, this may be addressed if the SSB associated with thecontention based RA resource has a one-to-one relationship with acandidate CSI-RS which is considered by a specific terminal and it isknown to both of the network and the terminal. However, this case maynot occur frequently, and it should be noted that, if the contentionbased RA resource based on the SSB and the contention free RA resourcebased on the CSI-RS exist together, the correlation between theresources and the beams may be a many-to-one relationship (many CSI-RSsto one SSB, or one CSI-RS to many SSBs), in addition to the one-to-one.

Hence, if using the contention based RA, the terminal requires a methodfor providing accurate candidate beam information to the network. Fordoing so, the terminal may include its terminal information (e.g.,C-RNTI) and beam information (e.g., CSI-RS ID, CSI-RS measurement) in anuplink message (e.g., Msg3) transmitted from the terminal, in responseto a downlink RA preamble response message of the network in the RAprocedure. Now, the disclosure provides embodiments for transmittingsuch information and embodiments for prioritizing a logical channel.

FIG. 5 illustrates a flowchart of a terminal for performing a RAprocedure in a wireless communication system according to an embodimentof the disclosure. FIG. 5 illustrates an operating method of theterminal 120.

Referring to FIG. 5, in operation 501 the terminal may transmit acontention based RA channel (CB RACH) preamble. In operation 503, theterminal may receive a RA response (RAR) in response to the transmittedpreamble. In operation 505, the terminal may include a C-RNTI MAC-CE ina message to transmit (e.g., Msg3) using an uplink resource designatedby the RAR. In operation 507, the terminal determines whether theongoing CB RACH transmission is initiated by the BFR. If the CB RACHtransmission is initiated by the BFR, the terminal determines whetherthere is available (having a measurement value over a specificthreshold) CSI-RS resource in operation 509. For example, the terminaldetermines that the ongoing CB RACH transmission is initiated by theBFR, and determines whether a suitable CSI-RS resource is available. Ifthe CB RACH transmission is initiated by the BFR and the CSI-RS resourceis available, the terminal includes a BFR MAC-CE including an ID of theCSI-RS resource in a subsequent uplink transmission in operation 511.For example, the terminal may include the BFR MAC-CE including the ID ofthe CSI-RS resource in a Msg3 to transmit. In operation 513, theterminal performs the uplink transmission. For example, the terminal maytransmit the Msg3 using the resource allocated from the RAR.

In the embodiment of FIG. 5, the Msg3 may have a structure of FIG. 6,including the C-RNTI MAC-CE and the BFR MAC-CE including the ID of theCSI-RS resource.

FIG. 6 illustrates a Msg3 structure in a wireless communication systemaccording to an embodiment of the disclosure.

Referring to FIG. 6, the Msg3 may include a MAC subheader 602, a C-RNTIMAC CE 604, a MAC subheader 606, and a BFR MAC CE 608. At this time,logical channel prioritization for generating such a MAC CE may bedefined as shown in FIG. 7.

FIG. 7 illustrates a flowchart of a terminal for generating a MAC CE ina wireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 7, in operation 701 the terminal first adds a C-RNTIMAC-CE. In operation 703, the terminal, if available, adds a BFR MAC CE.In operation 705, the terminal adds other MAC CEs, if uplink grantremains. In other words, if capacity remains, the terminal may add otherMAC-CEs.

FIG. 8 illustrates a flowchart of a terminal for performing a RAprocedure in a wireless communication system according to an embodimentof the disclosure. FIG. 8 illustrates an operating method of theterminal 120.

Referring to FIG. 8, in operation 801 the terminal may transmit a CBRACH preamble. In operation 803, the terminal may receive an RAR inresponse to the transmitted preamble. Next, the terminal may include aspecific MAC-CE in a Msg3 to transmit using an uplink resourcedesignated by the RAR. For doing so, the terminal determines whether theongoing CB RACH transmission is initiated by the BFR in operation 805.If the CB RACH transmission is initiated by the BFR, the terminaldetermines whether there is available (having a measurement value over aspecific threshold) CSI-RS resource in operation 807. For example, theterminal determines whether the ongoing CB RACH transmission isinitiated by the BFR, and determines whether a suitable CSI-RS resourceis available.

If the CB RACH transmission is not initiated by the BFR or the CSI-RSresource is not available, the terminal includes a C-RNTI MAC-CE in theuplink transmission in operation 809. By contrast, if the CB RACHtransmission is initiated by the BFR or the CSI-RS resource isavailable, the terminal includes a BFR MAC-CE including the ID of theCSI-RS resource in the uplink transmission in operation 811. Inoperation 813, the terminal performs the uplink transmission. Forexample, the terminal may transmit a Msg3 using the resource allocatedfrom the RAR.

In the embodiment of FIG. 8, if all the conditions are satisfied, thatis, in operation 811, the BFR MAC-CE included in the Msg3 may be definedas shown in FIG. 9.

FIG. 9 illustrates a BFR MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 9, the MAC-CE may include a MAC subheader 902 and aBFR MAC CE 904.

In the embodiment of FIG. 8, if at least one condition is not satisfied,that is, in operation 809, the C-RNTI MAC-CE included in the Msg3 may bedefined as shown in FIG. 10.

FIG. 10 illustrates a C-RNTI MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 10, the MAC-CE may include a MAC subheader 1002 and aC-RNTI MAC CE 1004.

Logical channel prioritization for generating such a MAC CE may bedefined as shown in FIG. 11.

FIG. 11 illustrates a flowchart of a terminal for generating a MAC CE ina wireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 11, in operation 1101 the terminal first adds one of aC-RNTI MAC-CE or a BFR MAC-CE according to a condition. In operation1103, if uplink grant remains, the terminal adds other MAC CEs. In otherwords, if capacity remains, the terminal may add other MAC-CEs.

FIG. 12 illustrates a flowchart of a terminal for performing a RAprocedure in a wireless communication system according to an embodimentof the disclosure. FIG. 12 illustrates an operating method of theterminal 120.

Referring to FIG. 12, in operation 1201 the terminal may transmit a CBRACH preamble. In operation 1203, the terminal may receive an RAR inresponse to the transmitted preamble. Next, the terminal may include aspecific MAC-CE in a Msg3 to transmit using an uplink resourcedesignated by the RAR. For doing so, the terminal determines whether theongoing CB RACH transmission is initiated by the BFR in operation 1205.If the CB RACH transmission is initiated by the BFR, the terminaldetermines whether there is available (having a measurement value over aspecific threshold) CSI-RS resource in operation 1207. For example, theterminal determines whether the ongoing CB RACH transmission isinitiated by the BFR, and determines whether a suitable CSI-RS resourceis available.

If the CB RACH transmission is not initiated by the BFR, the terminalincludes a C-RNTI MAC-CE in uplink transmission in operation 1209. Forexample, the terminal may add the C-RNTI MAC-CE in the Msg3.

If the ongoing CB RACH transmission is initiated by the BFR and noCSI-RS resource is available (having the measurement value over thethreshold), the terminal includes a BFR MAC-CE including C-RNTI withoutCSI-RS information to transmit, in the uplink transmission in operation1211. For example, the terminal may include the BFR MAC-CE includingonly the C-RNTI without the CSI-RS information, in the Msg3.

If the ongoing CB RACH transmission is initiated by the BFR and theCSI-RS resource is available (having the measurement value over thethreshold), the terminal includes a BFR MAC-CE including both of theCSI-RS information and the C-RNTI, in the uplink transmission inoperation 1213. For example, the terminal may include the BFR MAC-CEincluding both of the CSI-RS information and the C-RNTI, in the Msg3.

In operation 1215, the terminal performs the uplink transmission. Forexample, the terminal may transmit the Msg3 using a resource allocatedfrom the RAR.

In the embodiment of FIG. 12, the BFR MAC-CE included in the Msg3 whiletransmitting the RACH due to the BFR may be defined as shown in FIG. 13.

FIG. 13 illustrates a BFR MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 13, the Msg3 may include a MAC subheader 1302 and aBFR MAC-CE 1304. Herein, the Msg3 may include a 1-bit indicator whichindicates whether the corresponding BFR MAC-CE includes the CSI-RSinformation (e.g., ID).

In the embodiment of FIG. 12, if any condition is not satisfied, thatis, in operation 1209, the C-RNTI MAC-CE included in the Msg3 may bedefined as shown in FIG. 14.

FIG. 14 illustrates a C-RNTI MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 14, the Msg3 may include a MAC subheader 1402 and aC-RNTI MAC CE 1404.

At this time, the logical channel prioritization for generating such aMAC CE may be defined as shown in FIG. 15.

FIG. 15 illustrates a flowchart of a terminal for generating a MAC CE ina wireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 15, in operation 1501 the terminal first adds one of aC-RNTI MAC-CE or a BFR MAC-CE according to a condition. In operation1503, if uplink grant remains, the terminal adds other MAC CEs. In otherwords, if capacity remains, the terminal may add other MAC-CEs.

FIG. 16 illustrates a flowchart of a terminal for performing a RAprocedure in a wireless communication system according to an embodimentof the disclosure. FIG. 16 illustrates an operating method of theterminal 120.

Referring to FIG. 16, in operation 1601 the terminal may transmit a CBRACH preamble. In operation 1603, the terminal may receive an RAR inresponse to the transmitted preamble. Next, the terminal may include aspecific MAC-CE in a Msg3 to transmit using an uplink resourcedesignated by the RAR. For doing so, the terminal determines whether theongoing CB RACH transmission is initiated by the BFR in operation 1605.If the CB RACH transmission is initiated by the BFR, the terminaldetermines whether there is available (having a measurement value over aspecific threshold) CSI-RS resource in operation 1607. For example, theterminal determines whether the ongoing CB RACH transmission isinitiated by the BFR, and a suitable CSI-RS resource is available.

If the CB RACH transmission is not initiated by the BFR, the terminalincludes a C-RNTI MAC-CE in uplink transmission in operation 1609. Forexample, the terminal may include the C-RNTI MAC-CE in the Msg3.

If the ongoing CB RACH transmission is initiated by the BFR and noCSI-RS resource is available (having the measurement value over thethreshold), the terminal includes a Type2 BFR MAC-CE in the uplinktransmission in operation 1611. For example, the terminal may includethe Type2 BFR MAC-CE in the Msg3 to transmit.

If the CB RACH transmission conducted again is initiated by the BFR andthe CSI-RS resource is available (having the measurement value over thethreshold), the terminal includes a Type1 BFR MAC-CE in the uplinktransmission in operation 1613. For example, the terminal may includethe Type1 BFR MAC-CE in the Msg3.

In operation 1615, the terminal performs the uplink transmission. Forexample, the terminal may transmit the Msg3 using a resource allocatedfrom the RAR.

In the embodiment of FIG. 16, the Type1 BFR MAC-CE included in the Msg3while transmitting the RACH may be defined as shown in FIG. 17.

FIG. 17 illustrates a Type1 BFR MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 17, the Msg3 may include a MAC subheader 1702 and aType1 BFR MAC CE 1704. Herein, the corresponding BFR MAC-CE may includeCSI-RS information (e.g., ID) and a C-RNTI.

In the embodiment of FIG. 16, the Type2 BFR MAC-CE included in the Msg3while transmitting the RACH may be defined as shown in FIG. 18.

FIG. 18 illustrates a Type2 BFR MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 18, the corresponding BFR MAC-CE may not includeCSI-RS information (e.g., ID), but include a C-RNTI. The Msg3 mayinclude a MAC subheader 1802 and a Type2 BFR MAC CE 1804. Herein, thecorresponding BFR MAC-CE may include CSI-RS information (e.g., ID) and aC-RNTI.

In the embodiment of FIG. 16, if any condition is not satisfied, thatis, in operation 1609, the C-RNTI MAC-CE included in the Msg3 may bedefined as shown in FIG. 19.

FIG. 19 illustrates a C-RNTI MAC-CE structure included in a Msg3 in awireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 19, the Msg3 may include a MAC subheader 1902 and aC-RNTI MAC CE 1904.

At this time, the logical channel prioritization for generating such aMAC CE may be defined as shown in FIG. 20.

FIG. 20 illustrates a flowchart of a terminal for generating a MAC CE ina wireless communication system according to an embodiment of thedisclosure.

Referring to FIG. 20, in operation 2001 the terminal first adds one of aBFR MAC-CE Type1 or a BFR MAC-CE Type2 according to a condition. Inoperation 2003, if uplink grant remains, the terminal adds other MACCEs. In other words, if capacity remains, the terminal may add otherMAC-CEs.

According to embodiments as described above, the terminal may transmitthe message including the BFR related information during the RAprocedure. In response, the base station may receive the messageincluding the BFR related information. From the message including theBFR related information, the base station may obtain the BFR relatedinformation and perform the BFR procedure.

According to other embodiment of the disclosure, the network may deliverspecific timer information to the terminal in advance using a downlinksignal (e.g., RRC signal, MAC signal, PHY signal, and the like). Hence,the terminal may determine whether to perform the BFR.

The timer may initiate if the terminal detects a beam failure problem

The detection of the beam failure problem may be recognized if one ormore indications/incidents occur within a specific time at theMAC/PHY/RRC.

The terminal may scan a new candidate beam before the timer expires.

If the new candidate beam is scanned before the time expires, BFRattempt may be performed.

Alternatively, even if the new candidate beam is scanned before the timeexpires, the terminal does not perform any BFR attempt, for example, thecontention free RA and/or the contention based RA, and may scan a betterbeam for a defined time.

If the new candidate beam is not scanned before the time expires, theterminal does not perform any BFR attempt, for example, the contentionfree RA and/or the contention based RA.

If the timer expires, the terminal may operate as follows.

If the new candidate beam is scanned before the time expires, theterminal may perform the contention free RA or the contention based RAusing the new beam as stated above.

If the new candidate beam is not scanned before the time expires, theterminal may terminate every BFR attempt, initialize related parameters,and terminate related operations.

Alternatively, if the new candidate beam is not scanned before the timeexpires, the terminal may terminate every BFR attempt, declare radiolink failure (RLF), and initiate a cell reselection procedure.

Now, embodiments relating to discontinuous receive (DRX) operationpaging occasion (PO) configuration are explained.

During the DRX operation, the terminal may monitor one PO per DRX cycle.To determine such a PO, a rule for determining a frame to be used as areference (hereinafter a ‘reference frame’) and the PO is required. Thedisclosure provides embodiments for defining the rule based on thenumber of SSBs and control resource set (CORESET) configurationinformation.

The reference frame may be determined based on Equation 1.(SFN+offset)mod T=(T div N)*(UE_ID mod N)Offset: 0 for nB>=T, 0 . . . 1 for nB=T/2; 0 . . . 3 for nB=T/4; 0 . . .7 for nB=T/8;and 0 . . . 15 for nB=T/16;  Equation 1

In Equation 1, SFN denotes a system frame number, offset denotes anoffset for the reference frame, T denotes the DRX cycle of the terminal,N denotes a minimum value among T and nB, UE_ID denotes identificationinformation of the terminal, and nB denotes a parameter configured bysystem information.

At least one of the parameters may be configured by the systeminformation. For example, T may be determined to a smaller value among aterminal unique DRX value and a default DRX value which is broadcastedas the system information, if an upper layer grants. If the terminalunique DRX value is not configured, the terminal may determine T to thedefault DRX value which is broadcasted as the system information. UE_IDmay be defined as ‘international mobile subscriber identify (IMSI) mod1024’.

The terminal may determine an index i_s based on Equation 2.i_s=floor(UE_ID/N)mod NsNs=max(1,nB/T);N:min(T,nB)  Equation 2

In Equation 2, i_s denotes the index for indicating the PO to bemonitored by the terminal, UE_ID denotes the identification informationof the terminal, N denotes the minimum value among T and nB, T denotesthe DRX cycle of the terminal, and nB denotes the parameter configuredby the system information.

For example, if i_s is 0, the terminal monitors a first PO. If i_s is 1,the terminal monitors a second PO. If i_s is 2, the terminal monitors athird PO. If i_s is 3, the terminal monitors a fourth PO.

The network may configure and broadcast a paging search space includingmonitoring-periodicity-physical downlink control channel (PDCCH)-slot,Monitoring-offset-PDCCH-slot, and Monitoring-symbols-PDCCH-within-slot,in the system information. The terminal determines a PDCCH monitoringoccasion based on Monitoring-periodicity-PDCCH-slot,Monitoring-offset-PDCCH-slot, and Monitoring-symbols-PDCCH-within-slotof the slot.

If Equation 3 is satisfied, the PDCCH monitoring occasion exists in aslot x in a radio frame y.(y*(number of slots in a radioframe)+x-Monitoring-offset-PDCCH-slot)mod(Monitoring-periodicity-PDCCH-slot)=0  Equation3

In Equation 3, y denotes a radio frame number including the PDCCHmonitoring occasion, x denotes a slot number including the PDCCHmonitoring occasion, Monitoring-offset-PDCCH-slot denotes an offset forthe PDCCH monitoring, and Monitoring-periodicity-PDCCH-slot denotes aperiod for the PDCCH monitoring.

A start symbol of the PDCCH monitoring occasion of the slot x is givenas Monitoring-symbols-PDCCH-within-slot. A length (e.g., a symbol unit)of the PDCCH monitoring occasion may be given in CORESET in associationwith the search space.

According to such paging search space configuration, the terminaldetermines a first PDCCH monitoring occasion. Herein, the PDCCHmonitoring occasions are sequentially numbered the index from zero (0)within a corresponding reference frame. The first PO (e.g., the POcorresponding to i_s=0) are 0-th through S−1-th PDCCH monitoringoccasions, where S denotes the number of SSBs. The second PO (e.g., thePO corresponding to i_s=1) are S-th through 2S−1-th PDCCH monitoringoccasions. The third PO (e.g., the PO corresponding to i_s=2) are 2S-ththrough 3S−1-th PDCCH monitoring occasions. The index is numbered asstated above.

FIG. 21 illustrates a configuration of a PDCCH monitoring occasion in awireless communication system according to an embodiment of thedisclosure. FIG. 22 illustrates a paging occasion (PO) monitored by aterminal in a wireless communication system according to an embodimentof the disclosure.

Referring to FIGS. 21 and 22, monitoring-periodicity-PDCCH-slot is 4,Monitoring-offset-PDCCH-slot is 0, Monitoring-symbols-PDCCH-within-slotis 01000000000000, and PDCCH CORESET Length in symbols is 4.

Referring to FIGS. 21 and 22, the reference frame determined by the basestation is SFN #0, and the determined i_s is 0. In addition, the numberof SSBs is 4 (i.e., S=4). In this case, a first PDCCH monitoringoccasion ranges from symbols 3 to 5 in the slot 0. A next PDCCHmonitoring occasion ranges from symbols 2 to 5 in a slot 4. Similarly,subsequent PDCCH monitoring occasions may be determined. Since the indexi_s of the terminal is 0, the terminal observes the first PO includingthe PDCCH monitoring occasions 0, 1, 2, and 3 as shown in FIG. 22. Inbrief, the PDCCH monitoring occasions may be defined as shown in Table1.

TABLE 1 PDCCH monitor occasion 0 = SFN 0, slot 0, symbols 2 to 5 PDCCHmonitor occasion 1 = SFN 0, slot 4, symbols 2 to 5 PDCCH monitoroccasion 2 = SFN 0, slot 8, symbols 2 to 5 PDCCH monitor occasion 3 =SFN 1, slot 2, symbols 2 to 5

FIG. 23 illustrates a configuration of a PDCCH monitoring occasion in awireless communication system according to an embodiment of thedisclosure. FIG. 24 illustrates a PO monitored by a terminal in awireless communication system according to an embodiment of thedisclosure.

Referring to FIGS. 23 and 24, as another example of the paging searchingconfiguration, Monitoring-periodicity-PDCCH-slot is 1,Monitoring-offset-PDCCH-slot is 0, Monitoring-symbols-PDCCH-within-slotis 01000000000000, and PDCCH CORESET Length in symbols is 4.

In the embodiment of FIG. 23, the reference frame determined by the basestation is SFN #0, and the determined i_s is 0. In addition, the numberof SSBs is 6 (i.e., S=6). In this case, a first PDCCH monitoringoccasion ranges from symbols 2 to 5 in a slot 0. A next PDCCH monitoringoccasion ranges from symbols 2 to 5 in a slot 1. Similarly, subsequentPDCCH monitoring occasions may be determined. Since the index i_s of theterminal is 0, the terminal observes the first PO including the PDCCHmonitoring occasions 0, 1, 2, 3, 4, and 5 as shown in FIG. 24. In brief,the PDCCH monitoring occasions may be defined as shown in Table 2.

TABLE 2 PDCCH monitor occasion 0 = SFN 0, slot 0, symbols 2 to 5 PDCCHmonitor occasion 1 = SFN 0, slot 1, symbols 2 to 5 PDCCH monitoroccasion 2 = SFN 0, slot 2, symbols 2 to 5 PDCCH monitor occasion 3 =SFN 0, slot 3, symbols 2 to 5 PDCCH monitor occasion 4 = SFN 0, slot 4,symbols 2 to 5 PDCCH monitor occasion 5 = SFN 0, slot 5, symbols 2 to 5

Table 3 shows examples of the PO based on values of i_s and Ns.

TABLE 3 Ns i_s = 0 i_s = 1 i_s = 2 i_s = 3 1 1st PO i.e., N/A N/A N/A 0to S-1th PDCCH monitoring occasions. 2 1st PO i.e., 0 2nd PO i.e., S toN/A N/A to S-1th 2S-1th PDCCH PDCCH monitoring monitoring occasionsoccasions 3 1st PO i.e., 2nd PO i.e., S to 3rd PO i.e., 2S to 2nd POi.e., 0 to S-1th 2S-1th PDCCH 3S-1th PDCCH 3 to PDCCH monitoringmonitoring 4S-1th PDCCH monitoring occasions occasions monitoringoccasions occasions

Now, embodiments for including information of on-demand systeminformation reception in the system information are described.Hereafter, a resource allocation method for requesting the on-demandsystem information, to be recognized by the terminal to receive theon-demand system information, is explained.

The terminal may request the on-demand system information from thenetwork using the contention based or content free RA. The disclosureprovides more general contention free terminal operations, and anefficient network configuration method.

On-demand system information (SI) request based on RA preamble (Msg1)

The terminal may request the on-demand system information which isrequired by the terminal, by transmitting a RA preamble to the network.In doing so, configuration parameter for the RA usable by the terminalmay be configured as many as parameters maxSI-Message indicating amaximum number of on-demand system information messages provided fromthe network as shown in Table 4. The parameter maxSI-Message may beconfigured by the network using an RRC message, a MAC message, or a PHYmessage.

TABLE 4 SI-Request-Config ::= SEQUENCE(SIZE(1..maxSI-Message)) OFSI-Request- Resources

If the list includes only one configuration entry, the correspondingconfiguration may be evenly used in all of the on-demand systeminformation messages provided from the network. Otherwise, respectiveconfigurations may be sequentially applied to the on-demand systeminformation messages one to one in schedulingInfoList. TheschedulingInfoList includes a list of system information messagessupported by the cell, and may include transmission configurationinformation, such as periods, mapped system information blocks (SIBs),on-demand SI message broadcast status.

SchedulingInfoList and SI-request-config may be broadcast through SIB1,and may be included in a signal of other physical broadcast channel(PBCH). Alternatively, schedulingInfoList and SI-request-config may beincluded an RRC signal which is received and configured if the terminalaccesses the network, and may be configured using other SIB or other MACor PHY signal.

SI-Request-Resources may be configured based on a preamble index listand an SSB occasion mask indexes as shown in Table 5.

TABLE 5  SI-Request-Resources::= SEQUENCE {   ra-PreambleIndexList SEQUENCE(SIZE(1.. maximum number of SSB per Rach Occasion)) OFINTEGER(0..63),   ra-ssb-OccasionMaskIndex   INTEGER(0..15) OPTIONAL  }

With the configured schedulingInfoList and SI-request-config, theterminal may request the on-demand system information from the networkin a manner, to be described, based on ra-preambleindexlist ofSI-request-resources and #of SSBs per RACH occasion in the RACHconfiguration of the system information.

a) If #of SSBs per RACH occasion(N) is smaller than 1,

i. a size of ra-preambleindexlist is 1, and the terminal recognizesone-to-one mapping relationships between preambles ofra-preambleindexlist and SSB indexes associated with the RACH occasions.

b) If #of SSBs per RACH occasion(N) is greater than or equal to 1,

i. the size of ra-preambleindexlist is equal to #of SSBs per RACHoccasion(N), and the terminal recognizes one-to-N mapping relationshipsbetween the preambles of ra-preambleindexlist and the SSB indexesassociated with the RACH occasions. At this time, an i-th preamble ofra-preambleindexlist which is a preamble index list may be linked toeach SSB index as follows: mod (SSB_index, #of preambles in thelist)=i−1

or,

c) If #of SSBs per RACH occasion(N) is smaller than or equal to 1,

i. the size of ra-preambleindexlist is 1, and the terminal recognizesone-to-one mapping relationships between the preambles ofra-preambleindexlist and the SSB indexes associated with the RACHoccasions.

d) If #of SSBs per RACH occasion(N) is greater than 1,

i. the size of ra-preambleindexlist is equal to #of SSBs per RACHoccasion(N), and the terminal recognizes one-to-N mapping relationshipsbetween the preambles of ra-preambleindexlist and the SSB indexesassociated with the RACH occasions. At this time, the i-th preamble ofra-preambleindexlist which is the preamble index list may be linked toeach SSB index as follows: mod (SSB_index, #of preambles in thelist)=i−1.

Using such rules, the terminal may know the association between thepreambles of ra-preambleindexlist and the SSB indexes as shown in Table6.

TABLE 6 1st preamble in list corresponds to SSB Index 0, N, 2N, 3N andso on. 2nd preamble in list corresponds to SSB Index 1, N+1, 2N+1, 3N+1and so on  3rd preamble in list corresponds to SSB Index 2, N+2, 2N+2,3N+2 and so on To generalize: i^(th) preamble in the list corresponds toSSB index j*N+(i-1) where j = 0, 1, 2, and so on.

In other embodiment of the disclosure, the terminal may define thenumber of the preambles in ra-preambleindexlist as N, and apply theassociation of the SSB index.

In other embodiment of the disclosure, the terminal may define thenumber of messages in maxSI-Message as N, and apply the association ofthe SSB index.

It is provided that there are configurations which are greater than 1 inSI-Request-Config of Table 4, and smaller than the number of themaxSI-Messages. Provided that the number of on-demand system informationmessages in schedulinginfolist is N1 and the number ofSI-Request-Resources in SI-Request-Config is N2, correspondingconfigurations may be applied to the on-demand system information inschedulingInfoList as follows.

Method 1: The terminal may apply the configuration by N1/N2. Forexample, if N1 is 6 and N2 is 3, the terminal may sequentially group andapply the on-demand system information messages in schedulinginfolist byN1/N2=6/3=2, to SI-Request-Resources in SI-Request-Config. If N1/N2 isnot evenly divided to an integer, the terminal may round down. Forexample, if N1/N2=7/3=2.333, the terminal may apply the on-demand systeminformation messages by two.

Method 2: The terminal may sequentially apply SI-Request-Resources ofN2-ary SI-Request-Config to N2-ary on-demand system information messagesof on-demand system information messages in N1-ary schedulinginfolist,and commonly apply SI-Request-Resources of SI-Request-Config firstly orlastly to remaining (N1-N2)-ary on-demand system information messages.

Method 3: The terminal may sequentially apply SI-request-resources ofN2-ary SI-Request-Config to N2-ary on-demand system information messagesof the on-demand system information messages in N1-aryschedulinginfolist, and sequentially apply SI-Request-Resources ofN2-ary SI-Request-Config to N2-ary on-demand system information messagesof the remaining (N1-N2)-ary on-demand system information messages, thusconfiguring N1 in total. For example, if N1=6 and N2=4, the terminal maysequentially apply SI-request-resources of SI-request-config toon-demand system information messages of first four schedulinginfolist,and sequentially apply first two SI-request-resources ofSI-request-config to on-demand system information of the other twoschedulinginfolist.

Method 4: The terminal may include and provide a list of the on-demandsystem information, sImessageindexlist of schedulinginfolist to applythe corresponding configuration as shown in Table 7, inSI-request-config.

TABLE 7 SI-Request-Resources::=  SEQUENCE {  ra-PreambleIndexList  SEQUENCE(SIZE(1.. maximum number of SSB per Rach Occasion)) OFINTEGER(0..63),  ra-ssb-OccasionMaskIndex    INTEGER(0..15) OPTIONAL, sImessageIndexList SEQUENCE(SIZE(1.. maxSI-Message)) OF INTEGER(0..maxSI-Message-1), }

According to an embodiment of the disclosure, the system informationmessage may be received as below.

The system information message may include system information of otherSIB type than SIB1. SIB1 provides connections between such SIBs and thesystem information messages. Each SIB is included in only one systeminformation message. The system information message is transmitted in aspecific system information-window of a time axis which occurs on aperiodic basis. The network may include and transmit a systeminformation transmit window number, for example, Wn in each systeminformation message.

In an embodiment of the disclosure, different system informationmessages having the same system information transmit window number Wnmay be transmitted in the same system information-window.

According to another embodiment of the disclosure, the systeminformation transmit window number may be provided implicitly. Thenetwork and the terminal may know the system information transmit windownumber n of an n-th system information message in SIB1, andtransmit/receive the system information message in a system informationtransmit window corresponding to n.

Periods of the system information message and the system informationtransmit window may be provided from the network. Such periodinformation may be included in a broadcast message, such as minimumsystem information (MSI), SIB1, or may be included in a downlinkdedicated signal transmission, such as a response to a terminal'srequest or a handover command.

Using the system information transmit window number, the systeminformation message period, and the system information transmit windowlength, the terminal may configure a system information receive windowfor receiving the system information message. In an advanced system, theterminal does not have to monitor the PDCCH to receive the systeminformation message in the system information receive window.

The information sharing of the network and the terminal are as follows.

Step 1: The terminal determines the system information window number Wnof a specific system information message to receive. Wn is transmittedby the network in each system information message.

In other embodiment of the disclosure, the system information transmitwindow number may be provided implicitly. The network and the terminalmay know the system information transmit window number n of the n-thsystem information message in SIB1, and transmit/receive the systeminformation message in the system information transmit windowcorresponding to n.

Step 2: The terminal determines a length of the system informationreceive window to a positive integer X=(Wn−1)*w, where w denotes thelength of the system information-window and is expressed in a slot unit.

Step 3: The terminal determines a start point of the system informationreceive window. The corresponding start point is a slot N1 in a radioframe N2, and may be determined as [N2*(number of slots in a radioframe)+N1+Offset) mod T=X. T denotes the system information messageperiod in the slot unit and is provided in remaining minimum systeminformation, remained system information (RMSI) (e.g., SIB1). Offset isprovided in the RMSI (e.g., SIB1) in the slot unit.

The number of slots in the radio frame is determined in advance by a subcarrier spacing (SCS) used by a corresponding system, and SCSinformation may be provided in MIB/SIB1. The system information receivewindow lasts by the slot length w and then terminates.

Step 4: The terminal in the system information receive window observesthe PDCCH to receive other system information (OSI). The terminaldetermines a PDCCH observation occasion according to OSI search spaceconfiguration. If the OSI search space is not configured in a designatedsystem information receive window or not received, the terminal mayobserve the PDCCH at a corresponding occasion using a PDCCH observationoccasion which is configured for the RMSI.

An apparatus and a method according to embodiments of the disclosureeffectively achieve the BFR in the system.

The methods according to the embodiments described in the claims or thespecification of the disclosure may be implemented in software,hardware, or a combination of hardware and software.

As for the software, a computer-readable storage medium storing one ormore programs (software modules) may be provided. One or more programsstored in the computer-readable storage medium may be configured forexecution by one or more processors of an electronic device. One or moreprograms may include instructions for controlling the electronic deviceto execute the methods according to the embodiments described in theclaims or the specification of the disclosure.

Such a program (software module, software) may be stored to a RA memory,a non-volatile memory including a flash memory, a read only memory(ROM), an electrically erasable programmable ROM (EEPROM), a magneticdisc storage device, a compact disc (CD)-ROM, digital versatile discs(DVDs) or other optical storage devices, and a magnetic cassette.Alternatively, the program may be stored to a memory combining part orall of those recording media. A plurality of memories may be equipped.

The program may be stored in an attachable storage device accessible viaa communication network, such as Internet, Intranet, local area network(LAN), wide LAN (WLAN), or storage area network (SAN), or acommunication network by combining these networks. The storage devicemay access the electronic device through an external port. A separatestorage device may access the device over the communication network.

In the specific embodiments of the disclosure, the elements included inthe disclosure are expressed in a singular or plural form. However, thesingular or plural expression is appropriately selected according to aproposed situation for the convenience of explanation and the disclosureis not limited to a single element or a plurality of elements. Theelements expressed in the plural form may be configured as a singleelement, and the elements expressed in the singular form may beconfigured as a plurality of elements.

While the disclosure has been shown and described with reference tovarious embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the disclosure as definedby the appended claims and their equivalents.

What is claimed is:
 1. A method performed by a terminal in wirelesscommunication system, the method comprising: receiving, from a basestation, system information including at least one parameter for apaging; and monitoring a paging occasion (PO) in a discontinuousreception (DRX) cycle based on the at least one parameter for thepaging, wherein the PO corresponds to a set of one or more physicaldownlink control channel (PDCCH) monitoring occasions for the paging,wherein the number of the one or more PDCCH monitoring occasions for thepaging in the set is the number of at least one transmittedsynchronization signal block (SSB), wherein PDCCH monitoring occasionsare sequentially numbered from zero (0) in a radio frame for the paging,wherein an index number of a starting PDCCH monitoring occasion of thePO is a multiplication of ‘S’ and an index ‘i_s’ of the PO, and whereinthe ‘S’ is the number of at least one transmitted SSB.
 2. The method ofclaim 1, wherein the monitoring of the PO comprises monitoring one POper the DRX cycle, and wherein the one PO is located in a radio frameincluding one or more paging occasions.
 3. The method of claim 1,wherein the at least one parameter includes information on an offset,and wherein the PO is located in a radio frame that is determined basedon the offset identified from the system information, the DRX cycle forthe terminal, and an identifier (ID) of the terminal.
 4. The method ofclaim 1, wherein the one or more PDCCH monitoring occasions for thepaging are configured in a paging search space indicated by the systeminformation, and wherein the PO is indicated by an index that isdetermined based on an ID of the terminal and at least one valueassociated with the DRX cycle for the terminal.
 5. The method of claim4, wherein the ID of the terminal is an identity of the terminal mod1024.
 6. The method of claim 1, wherein the monitoring of the POcomprises: identifying the radio frame for the PO based on the at leastone parameter for the paging; identifying the index ‘i_s’ of the PO; andmonitoring (i_s+1)^(th) paging occasion based on the radio frame, andwherein the radio frame is identified based on a following equation:(SFN+offset)mod T=(T div N)*(UE_ID mod N) where ‘SFN’ refers to a systemframe number of the radio frame, ‘offset’ refers to a paging offsetconfigured by the system information, ‘T’ refers to the DRX cycle, ‘N’refers to a value associated with the ‘T’, and ‘UE_ID’ refers to anidentifier (ID) of the terminal.
 7. The method of claim 1, wherein ak-th PDCCH monitoring occasion of the one or more PDCCH monitoringoccasions of the set corresponds to a k-th SSB of the at least onetransmitted SSB.
 8. A method performed by a base station in wirelesscommunication system, the method comprising: transmitting, to aterminal, system information including at least one parameter for apaging; and transmitting, to the terminal, a paging message in a pagingoccasion (PO) in a discontinuous reception (DRX) cycle, based on the atleast one parameter for the paging, wherein the PO corresponds to a setof one or more physical downlink control channel (PDCCH) monitoringoccasions for the paging, wherein the number of the one or more PDCCHmonitoring occasions for the paging in the set is the number of at leastone transmitted synchronization signal block (SSB), wherein PDCCHmonitoring occasions are sequentially numbered from zero (0) in a radioframe for the paging, wherein an index number of a starting PDCCHmonitoring occasion of the PO is a multiplication of ‘S’ and an index‘i_s’ of the PO, and wherein the ‘S’ is the number of at least onetransmitted SSB.
 9. The method of claim 8, wherein the PO is located ina radio frame including one or more paging occasions.
 10. The method ofclaim 8, wherein the PO is located in a radio frame that is determinedbased on an offset identified from the system information, the DRX cyclefor the terminal, and an identifier (ID) of the terminal.
 11. The methodof claim 8, wherein the one or more PDCCH monitoring occasions for thepaging are configured in a paging search space indicated by the systeminformation, and wherein the PO is indicated by an index that isdetermined based on an ID of the terminal and at least one valueassociated with the DRX cycle for the terminal.
 12. The method of claim11, wherein the ID of the terminal is a subscriber identity of theterminal mod
 1024. 13. The method of claim 8, wherein a k-th PDCCHmonitoring occasion of the one or more PDCCH monitoring occasions of theset corresponds to a k-th SSB of the at least one transmitted SSB.
 14. Aterminal in wireless communication system, the terminal comprising: atleast one transceiver; and at least one processor coupled to the atleast one transceiver and configured to: receive, from a base station,system information including at least one parameter for a paging, andmonitor a paging occasion (PO) in a discontinuous reception (DRX) cyclebased on the at least one parameter for the paging, wherein the POcorresponds to a set of one or more physical downlink control channel(PDCCH) monitoring occasions for the paging, wherein the number of theone or more PDCCH monitoring occasions for the paging in the set is thenumber of at least one transmitted synchronization signal block (SSB),wherein PDCCH monitoring occasions are sequentially numbered from zero(0) in a radio frame for the paging, wherein an index number of astarting PDCCH monitoring occasion of the PO is a multiplication of ‘S’and an index ‘i_s’ of the PO, and wherein the ‘S’ is the number of atleast one transmitted SSB.
 15. The terminal of claim 14, wherein the POis located in a radio frame that is determined based on an offsetidentified from the system information, the DRX cycle for the terminal,and an identifier (ID) of the terminal.
 16. The terminal of claim 14,wherein the one or more PDCCH monitoring occasions for the paging areconfigured in a paging search space indicated by the system information,and wherein the PO is indicated by an index that is determined based onan ID of the terminal and at least one value associated with the DRXcycle for the terminal.
 17. The terminal of claim 16, wherein the ID ofthe terminal is an identity of the terminal mod
 1024. 18. The terminalof claim 14, wherein the at least one processor is, in order to monitorthe PO, configured to: identify the radio frame for the PO based on theat least one parameter for the paging, identify the index ‘i_s’ of thePO, and monitor (i_s+1)^(th) paging occasion based on the radio frame,and wherein the radio frame is identified based on a following equation:(SFN+offset)mod T=(T div N)*(UE_ID mod N) where ‘SFN’ refers to a systemframe number of the radio frame, ‘offset’ refers to a paging offsetconfigured by the system information, ‘T’ refers to the DRX cycle, ‘N’refers to a value associated with the ‘T’, and ‘UE_ID’ refers to anidentifier (ID) of the terminal.
 19. The terminal of claim 14, wherein ak-th PDCCH monitoring occasion of the one or more PDCCH monitoringoccasions of the set corresponds to a k-th SSB of the at least one SSB.20. The terminal of claim 14, wherein the at least one processor is, inorder to monitor the PO, configured to monitor one PO per the DRX cycle,and wherein the one PO is located in a radio frame including one or morepaging occasions.
 21. The terminal of claim 14, wherein PDCCH monitoringoccasions are sequentially numbered from zero (0) in a radio frame forthe paging, wherein an index number of a starting PDCCH monitoringoccasion of the PO is a multiplication of ‘S’ and an index ‘i_s’ of thePO, and wherein the ‘S’ is the number of at least one transmitted SSB.22. A base station in wireless communication system, the base stationcomprising: at least one transceiver; and at least one processor coupledto the at least one transceiver and configured to: transmit, to aterminal, system information including at least one parameter for apaging, and transmit, to the terminal, a paging message in a pagingoccasion (PO) in a discontinuous reception (DRX) cycle, based on the atleast one parameter for the paging, wherein the PO corresponds to a setof one or more physical downlink control channel (PDCCH) monitoringoccasions for the paging, wherein the number of the one or more PDCCHmonitoring occasions for the paging in the set is the number of at leastone transmitted synchronization signal block (SSB), wherein PDCCHmonitoring occasions are sequentially numbered from zero (0) in a radioframe for the paging, wherein an index number of a starting PDCCHmonitoring occasion of the PO is a multiplication of ‘S’ and an index‘i_s’ of the PO, and wherein the ‘S’ is the number of at least onetransmitted SSB.
 23. The base station of claim 22, wherein a k-th PDCCHmonitoring occasion of the one or more PDCCH monitoring occasions of theset corresponds to a k-th SSB of the at least one transmitted SSB. 24.The base station of claim 22, wherein the PO is located in a radio frameincluding one or more paging occasions.
 25. The base station of claim22, wherein the PO is located in a radio frame that is determined basedon an offset identified from the system information, the DRX cycle forthe terminal, and an identifier (ID) of the terminal.
 26. The basestation of claim 22, wherein the one or more PDCCH monitoring occasionsfor the paging are configured in a paging search space indicated by thesystem information, and wherein the PO is indicated by an index that isdetermined based on an ID of the terminal and at least one valueassociated with the DRX cycle for the terminal.
 27. The base station ofclaim 26, wherein the ID of the terminal is a subscriber identity of theterminal mod 1024.